// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/test/test_file_util.h"

#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <string>

#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "build/build_config.h"

namespace base {

namespace {

    // Deny |permission| on the file |path|.
    bool DenyFilePermission(const FilePath& path, mode_t permission)
    {
        struct stat stat_buf;
        if (stat(path.value().c_str(), &stat_buf) != 0)
            return false;
        stat_buf.st_mode &= ~permission;

        int rv = HANDLE_EINTR(chmod(path.value().c_str(), stat_buf.st_mode));
        return rv == 0;
    }

    // Gets a blob indicating the permission information for |path|.
    // |length| is the length of the blob.  Zero on failure.
    // Returns the blob pointer, or NULL on failure.
    void* GetPermissionInfo(const FilePath& path, size_t* length)
    {
        DCHECK(length);
        *length = 0;

        struct stat stat_buf;
        if (stat(path.value().c_str(), &stat_buf) != 0)
            return NULL;

        *length = sizeof(mode_t);
        mode_t* mode = new mode_t;
        *mode = stat_buf.st_mode & ~S_IFMT; // Filter out file/path kind.

        return mode;
    }

    // Restores the permission information for |path|, given the blob retrieved
    // using |GetPermissionInfo()|.
    // |info| is the pointer to the blob.
    // |length| is the length of the blob.
    // Either |info| or |length| may be NULL/0, in which case nothing happens.
    bool RestorePermissionInfo(const FilePath& path, void* info, size_t length)
    {
        if (!info || (length == 0))
            return false;

        DCHECK_EQ(sizeof(mode_t), length);
        mode_t* mode = reinterpret_cast<mode_t*>(info);

        int rv = HANDLE_EINTR(chmod(path.value().c_str(), *mode));

        delete mode;

        return rv == 0;
    }

} // namespace

bool DieFileDie(const FilePath& file, bool recurse)
{
    // There is no need to workaround Windows problems on POSIX.
    // Just pass-through.
    return DeleteFile(file, recurse);
}

#if !defined(OS_LINUX) && !defined(OS_MACOSX)
bool EvictFileFromSystemCache(const FilePath& file)
{
    // There doesn't seem to be a POSIX way to cool the disk cache.
    NOTIMPLEMENTED();
    return false;
}
#endif

bool MakeFileUnreadable(const FilePath& path)
{
    return DenyFilePermission(path, S_IRUSR | S_IRGRP | S_IROTH);
}

bool MakeFileUnwritable(const FilePath& path)
{
    return DenyFilePermission(path, S_IWUSR | S_IWGRP | S_IWOTH);
}

FilePermissionRestorer::FilePermissionRestorer(const FilePath& path)
    : path_(path)
    , info_(NULL)
    , length_(0)
{
    info_ = GetPermissionInfo(path_, &length_);
    DCHECK(info_ != NULL);
    DCHECK_NE(0u, length_);
}

FilePermissionRestorer::~FilePermissionRestorer()
{
    if (!RestorePermissionInfo(path_, info_, length_))
        NOTREACHED();
}

} // namespace base
